皮皮学，免费搜题
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【单选题】
下列哪种化合物是一种维生素 A 原?A.
视黄醛；
B.
β —胡萝卜素；
C.
麦角固醇；
D.
萘醌；
E.
胆固醇
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皮皮学刷刷变学霸
举一反三
【简答题】对2层高的2元完全正则树,可知 (1)有_______片树叶(第一空) (2)有_______个内点(第二空) (2)有_______个分支点(第三空) (3)有_______个顶点(阶数)(第四空) 提示:相关概念见教材第181-182页。2层高的2元完全正则树如下图所示:
【单选题】S ome students may find it hard an academic environment again after travelling or working for a year.
A.
to get used to
B.
to used to
C.
to get used
D.
get used to
【简答题】智慧职教平台的全称是 ，APP是 。A. B.
【单选题】The students are busy ______ the examination.
A.
preparing for
B.
preparing
C.
to prepare
D.
to prepare for
【简答题】A．To test students through computers. B．To store statistics about students. C．To help professors do research work. D．To aid students in registration.
【单选题】A teacher must see to it that every one of his students develops .
A.
extremely
B.
fairly
C.
hurriedly
D.
properly
【单选题】What the teacher said in class set all the _____ a lot. [ ]
A.
present students to think
B.
students present thinking
C.
present students thinking
D.
students present to think
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